The determination of the fat mass is of relevant importance in many fields.
In the medical field, for example, the determination of the fat mass allows to diagnose and prevent and helps to plan eventual interventions aimed at both losing and putting on weight.
The determination of the fat mass can also be useful in animals, both alive and slaughtered, for instance for qualitative and evaluative purposes and for eventual subsequent slaughters.
The knowledge of the fat mass in a cut of meat, for example ham, can be useful to quantify the quality and/or the nutritional properties thereof.
In the known art, there exists an Italian patent by the same inventor of this now method and in the name of Akern S.r.l. under number 0001343130 entitled:
“A process for the determination of the density of a human body or other, and a device for realizing it”.
The patent describes a methodology, with relative apparatus, that allows to determine the volume from which to obtain, in association with the weight, an estimation of the body density and from which it is possible to derive the content of fat mass (for example, of a person and also of a simple cut of meat already slaughtered).
The method foresees the use of one or two tele-cameras, the acquisition of at least two images and the use of a frame of a known size.
Basically, a location on which the subject (for example a person) is placed is foreseen.
The person is standing inside the frame and in front of a background of a white, not reflecting, homogeneous colour.
Two tele-cameras (or a single one when the person is placed on a rotating support whose rotation is governed by a micro-controller or the subject is capable of rotating, but with a monitored rotation of 90°) allow to acquire two images of the subject orthogonal between them and, in particular, a view with the subject placed frontally (antero-posterior projection) and a view with the subject placed abreast (latero-lateral projection).
The idea, therefore, consists in comparing the two areas (A1, A2) of the two profiles acquired on the basis of the concept that the area of the entire image delimited by a frame furnished with known sizes is in part “occupied” or filled in by the profiles taken and therefore, from here, it is possible to determine by proportionality a total body surface from which to derive also the estimation of the body volume.
Basically, once the two images are acquired, a software processes a comparison of colour of the pixels between background and profile in such a way as to distinguish the profile and obtain its area.
Once the two areas (A1, A2) are known, a specific formula obtains an estimation of the volume. Known the weight of the body under exam, the determination of the density is made as the relation between volume and weight and subsequently the estimation of the fat mass takes place.
The method described, though functioning, suffers from some technical inconveniences.
The apparatuses required are cumbersome and relatively expensive. In particular, a tele-camera is required, as well as a support base provided with a contour (frame) of a known size and sufficiently wide as to contain also subjects with big body masses and sufficiently high as to allow the sample under exam to be erect. If the support base is not of the assisted or anyway controlled rotation type, it is even necessary the use of two tele-cameras appropriately placed or it is necessary to obtain a rotation of the subject under exam of 90° as precise as possible, in such a way as to acquire images normal among them.
All this means an apparatus that is expensive and cumbersome, destined to specialized structures, and operated by operators appropriately trained, rendering the determination of the fat mass a check that is only feasible in specialized locations.
A further document is also known, available on the Internet with the title “Estimation of body mass distribution using projective image”.
Such a document describes a method for determining a fat mass by using image acquisition. In particular, two images have to be acquired, that is a front one and a lateral one, as described on page 11 of such a document. Such an acquisition of two images is essential for being able to calculate the fat mass in accordance with the formula used that requires the knowledge of ovoid volumes.
A calibration in the two images takes place by inserting, in the image to be acquired, an object of known size, as described on page 8. In this manner, a correlation is obtained between one or more pixels and a unit of measure. The images are processed to eliminate any interference. Last, the images are processed converting them into a greyscale, as described on page 12, in such a way as to calculate a volume. The volume, as described on page 13, is calculated by creating about fifty transversal sections of the subject in the two images and measuring the height (h) and the length (a, b) of each section. In this manner, the surface of each ovoid section (elliptical section) can be calculated and, as a consequence, the overall volume can be obtained as the sum of all the volumes calculated.
Such a method presents many technical inconveniences.
First of all, it is necessary to acquire two images to have a volume. Consequently, the processing of the images and the consequent calculation results to be heavier.
The processing described takes place through Matlab, which is a complex and expensive programme. Moreover, the calculation formula used renders obligatory not only the acquisition of two images but also the determination of the correlation between pixel and a real unity of measure to obtain a body volume that has to be necessarily precise. Only in this way is it possible to determine the essential density thereof to apply the formulas of Siri and of Brozek to obtain the body composition. This renders the procedure even more difficult.